Indicating system



Sept. 28, 1943. H. E. HERSHEY INDICATING SYSTEM Filed April 26, 1941 Sheets-Sheet l FIREST FLOOR SWWCH H FIRST FLOOR PULSNG sun-nous HMO Hem RIEO J/ STAT! ON STAflON SECOND FLOOR seceuo FLOOR STATIONS swaTcH l2 INVENTOR. HARRY E. HERSHEY g \i dM M ATTORNEYS TRANSFER- f K IE5!- RISO Sept. 28, 1943. H. E. HERSHEY 2,330,355

INDICATING SYSTEM Filed April 26, 1941 3 Sheets-Sheet 2 FIRST FLOOR SWITGH ll l65a. fi 26:

RESET CLEAR OUT SWITCHING M ROUP s LE T DFSPLAY WEE- uT SWITCH 20o zea -g 204 o or G O J RLSE 2m 0 2oz D c I D a 20? f 203 O o o a x SECOND FLOOR SWITCH I2 I I INVENTOR. g E HARRY awenswzx' 1 I BY ATTORNEYS Filed April 26, 1941 3 Sheets-Sheet 3 INVENTOR. HARRY E. HERSHEY ATTo yEYs Patented Sept. 28, 1943 INDICATING SYSTEM Harry E. Hershey, Chicago, 111., assignor to Automatic Electric Laboratories, Inc., a corporation of Delaware Application April 26, 1941, Serial No. 390,621

10 Claims.

The present invention relates to systems for indicating the location of one or more persons or objects which may be located in different zones of a plural zone area, and more particularly to improvements in systems for indicating at several points the locations of a large number of doctors who may be variously occupied on the difierent floors or in the different wardsof-a large hospital. 1

It is an object of the present invention to provide a system of the character indicated, which is of simple and economical arrangement, is positive and reliable in operation, and may be controlled to provide accurate data as to the whereabouts of a large number of persons or objects.

Another object of the invention is to provide an improved system of the character described, wherein the display board or boards of the system may be controlled by or on behalf of any one of the persons or objects from any one of a large number of control stations which are conveniently located throughout the zoned area.

It is a further object of the invention to provide an improved system of the character described, wherein like portions of a pluralityof display boards which are variously located in the zoned area, may be controlled in unison in response to control operations performed at any one of the control stations. 1

It is another object of the invention to provide an improved system of the character described, wherein the section of each display board which corresponds to any personor object may be selectively controlled from any control station to wipe out an existing display or to reset the section to display a new indication.

It is a still further object of the invention to provide 'an improved system of the character described, wherein each section of each display board may be blanked from a control station located in an entrance zone of the area.

It is still another object of the invention to provide an improved system of the character described, wherein each display board may be controlled from the entrance zone station to indicate the presence in the zoned area of each person or object posted on the display boards Without indicating the particular zone in which such person or object may be located.

In the illustrated embodiment of the invention there is provided a system which includes display boards and one or more control stations on each floor of a large hospital. The entrance Zone station of the hospital is located in the lobby through which the members of the hospital staff enter the building. Each display board is equipped with a plurality of display units which individually correspond to the doctors attached to the staff of the hospital, and each of the control stations, with the exception of the lobby station, is provided with a signal transmitting device for selecting and controlling the display units of the various boards. More specifically,

the display units are controlled from the con trol stations through automatic switches which 1 are individual to the hospital floors and each of which has access to all of the display units. The arrangement of these switches is such that one of two signals, both designating a particular doctor, is transmitted to a switch from its associated control station, the display units corresponding to that doctor are selected, the existing display thereof, if any, is wiped out, and a new display is set up indicating the floor or zone wherein the operated control station is located. This change in display is effected concurrently at all of the display boards, so that a Visual indication is given at all points as to the zone where the particular doctor may be located. The automatic switches individual to the various floors are further arranged so that if the other of the two signals designating a particular doctor is transmitted to one of the switches from an associated control station, thedisplay units 'corresponding to that doctor are selected and the indications previously displayed thereby are wiped out without resetting the units to display new indications. Provisions are also made in the system whereby indications displayed by the units corresponding to a particular doctor, may also be wiped out through the selective operation of key controlled switches provided at the lobby station. This equipment also includes keys which may be operated to control the display units individual to thevarious doctors so that indications are posted on the boards which show that particular doctors'are somewhere in the hospital, without indicating the exact floor where such doctors may be located.

The novel features believed to be characteristic of the invention are set forth with particularity in the appended claims. The invention, both as to its organization and method of operation, to-

gether with further objects and advantages thereof, will best be understood by reference to the specification taken in connection with the accompanying drawings in which Figs. 1, 2 and 3,.

when laid side by side in the order named, indicate a portion of the equipment provided ina SI, etc., which individually correspond to the doctors whose location is to be posted on the board. For example, the display unit 26 maybe utilized to indicate the location of the doctor who is assigned the identification number 165, and the display unit 29 may be utilized to; indicate the location of the doctor who i assigned the identification number 265. The various display boards are of identical construction, and, as will be pointed out more fully below, are so arranged that eachset of display units. corresponding to a particular doctor are controlled in unison. The individual display units of the boards are also identical in arrangement. Briefly described, the display unit 26 comprises apilot lamp I65), which when energized indicates that the doctor No. 165 is somewhere in the hospital, and a plurality of individual floor lamps 333, 334, 339, etc., which individually correspond to the various floors of the hospital. Each of the latter lamps when energized indicates that the doctor No. 165 may be located on the corresponding floor. The

display units common to the doctor No. 165 are controlled by a plurality of lamp control relays R333, R345), R396, etc., which are individual to the various floors and floor indicatinglamps.

The relay equipment provided to control the several display boards also includes a set ofcommon relays for each doctor postedon the boards. Thus for controlling the floor and pilot lamps of the display units individ' ll tothe doctor No; 165, the common relays R306, I t and R328 ,areprovided. An identical set 01 common relays IS, individual to the. doctor No. 2G5, is schematically indicated in the drawings.

The control of thevariousdisplay boards is effected. from control stations. which are con veniently locatedthroughout the hospital. specifically, an in andbut entrance ,station I3 is provided in the entrance zone orlobby-of the. hospital, and each floor of the hospital is equipped with. one or more control stations. Thus the first floor of the building is provided with three stations A, B and C, each of which includes a signal transmitting device Idl, a. hold key I04, and a pilot lamp I65. The hold keys I04 are of the Well-known locking. type. Each signal transmitting device I is of the dial-operated type conventionally used at the sub-stations of auto. matic telephone systems, and comprises a; set of pulsing springs I62 and a set of off-normal springs I93. The lobby or entrance zone stationldcomprises a plurality ofkey controlled switches and pilot lamps individual to t1 e doctors who are attached to the hospital staff and whose names are posted on the various display boards. More specifically, an in key, an out key, and apilot lamp is provided for each of the doctors. Thus the lobby station control panel. ,is equipped with an .in key I65c, an out key I65cl,,and aspilot lamp I65 which are for the individual use of the doctor who is assignedithe identification num: her 185., Similarly, this control panel. includes More an in key 2650, an out key 255d, and a pilot lamp 265e, which ar provided for the individual use of the doctor assigned the identification numher 265. The keys IEEc, ifitid, 2550, 265d, etc., are of the well-known nonlocking type.

The selection and selective control of the relay equipment associated with the various display units of the display boards is effected through the provision of a plurality of automatic switches which are individual to the various floors and can only be controlled from the control stations provided on the correspondin floors. Thus an automatic switch I I is provided which has access to the relay equipment and display units for all of the doctors posted on the display boards and may be controlled only from the first floor control stations A, B and C. A second switch I2 individual toth control stations of the second floor is also. schematically illustrated in the drawings. These automatic switches are of identical circuit arrangement. .Briefiy described; the switch Ii comprises a two-motion switching mechanism of thewell-known Strowger type. This mechanism is equipped with four banks of contacts, each of which includes one hundred contact points. The contacts making up this contact fieldiare divided into ten levels often each, and each of the four banks has associated therewithone of the four wipers 26I to 2845, inclusive for the purpose of elevating these wipers to aposition opposite a desired level, and then rotating the same into engagement with a selected contact set ofv the selected level, rotary, and vertical magnets I60 and I 6| are included in the switching mechanism. The mechanism further comprises a release ma net I62, which when energized permits the wiper carriagestructure to be returned to rotary and vertical normal; twosets of, vertical ofi-normal springs I63 and IE4, whichare operated when the wiper. carriage structure is movedto anyvertical off-normal position, and a set .of rotary onnormal springs- 266. which are operated-into engagement when the wiper carriage structure is operated one step fromthe rotary normal position thereof. In order to control the various magnets ofthe Strowger; switching. mechanism and the relayv equipmentassociated with the display-boards, theautomatic switch I! is equipped with a plurality of: control relays and a minor switch 200 which functions as a group-select and display.-wipe-out switch in the manner fully described hereinafter. Briefly described, the minor switchlfill comprises two sets of contacts having eleven contact points each, wipers 2G! and 262 individually associated with the contact sets, an operating magnet 283 for drivingthe wipers 2H and 202 from the illustrated normalpositions thereof to selected off-normal positionsareleasemagnet, 204 for returning. the enumerated wipers to normal, and a set of cit-normal springs 2% which are operated into engagement when the wipers of the switch are moved off-normal. The relay equipment of the switch ,I I .includes a pulsing relay RI I3, ahold rela RIZFI, a release relayRl30, a pair of transfer relays RIM) and RIBO, a wipe out relay RZUJ; acutoff relay R220, a reset relay R230, a clear out relay R240; and a switching relay 1 :258.. Of the enumerated'relays, the relays RIZU, 1%!30; RIM] and-RZIOare ofthe well-known slow-to-release type, while the relays R220 and R230 are of the conventional slow-to-operate type.

Current for energizing the indicating lamps, the lamp control relays, the operating. magnets of the: Strowger switching mechanisms, and the control relays of the automatic switches, is supplied from a common direct current source, the positive terminal of which is connected to a common bus conductor and to ground. The opposite terminal of this source is connected to a common negative bus conductor which terminates connections from the various relay, magnet and lamp terminals which are identified in the drawings by the negative polarity sign; For convenience in describing the circuits involved, the source of current, which may conventionally comprise a storag battery floated across the terminals of a charging rectifier, has not beenshown.

In considering the operation of the system, it may be assumed that the doctor who is assigned the identification number 165 enters the hospital the lobby and then proceeds to the first fioor where he will be occupied for a considerable period of time. Upon entering the hospital the doctor, conforming to hospital regulations, momentarily actuates the in key I650, thereby to complete a circuit for energizing the common relay R3! in parallel with the filaments of the pilot lamps I656 and I651. The relay RSIO, in

operating, locks to ground over a path including the contacts 3H and the contacts of the cu key Itfid, and in so doing completes an obvious circuit for maintaining the pilot lamp [651: energized after the in key I850 is released by the doctor No. 165. In operating, the relay RBIB also completes an alternative circuit for energizing the pilot lamp IEEJ in the display unit 26 of the first floor display board 25, this circuit extending from ground by way of the contacts of the out key H5561, the contacts 3H and 32L and the filament supplies the same information to observers who may consult the lamp panel at this station.

If thedocto-r No. 165, upon proceeding to the first floor of the hospital, desires to place himself on call, he may do so b actuating the transmitting device iili at one of the first floor control stations to dial the three digits of the identification number assigned to him. i. e., 165. Assuming that the station A is selected for this purpose, the doctor, before starting the dialing operation, may actuate the key IBM to its off-normal position, thereby to complete an obvious circuit for energizing in parallel the pilot lamps IGSa, I051), H350, etc, at the variou control stations on the first floor. The energization of these lamps serves to provide an indication that the first floor switch l i is busy. When the key lc la is actuated to its off-normal position a circuit including the series-connected pulsing springs of the transmitting devices iiiI is also completed for energizing the pulsing relay RI l9. This relay, in operating, closes its contacts Ill to complete an obvious circuit for energizing the hold relay RI2U. The relay :Rltil, upon operating, close its contacts iEI to prepare a pulsing circuit having three branches which respectively extend to the rotary magnet I66, the vertical magnet IEI and the operating magnet 29% of the minor switch 288. At its contacts I22, the relay RIZQ completes an obvious circuit for energizing the release relay R530. At its contacts I22, the relay RIZB also The energization of these particular pilot completes a circuit for energizing the transfer relay also, this circuit extending from ground;

magnet 293. At its contacts I52, the relay RIEO opens a point in the circuit for transmitting pulses to the vertical magnet i 6|. At its contacts l5l the relay BI 50 prepares a locking circuit for itself.

When the first digit 1 i dialed through operation of the transmitting device Iilla provided at the station A, the shunt springs I93 are moved into engagement to complete a path in shunt with the engaged springs of the key IBM, and the pulssp-rings I232 are opened and closed to transmit an impulse to the rela RI Iii. This relay, upon restoring at the beginning of the open-circuit pericd of the impulse, opens its contact II I to interrupt the operating circuit for the hold relay R128, and closes its contacts II 2 to complete the prepared circuit for energizing the transfer relay Rl-Zil in series with the operating magnet 203. The latter circuit extends from ground by way of the contacts H2,- I2I and I63b, the winding of Rial), the contacts 353 and the Winding of the magnet 28. to battery. When thus energized the relay El #18 operates and closes its contacts I43 to prepare an alternative pulsing circuit which bypasses the cit-normal contacts I632) and includes the off-normal contacts I83a. At its contacts iii. the relay Rial opens a point in the circuit for transmitting current pulses to the rotary magnet and the wipe out relay R299 in parallel. At-its contact I l l, the relay RIM completes the abovamentioned locking circuit for the relay R156, this circuit extending from ground byway of the contacts 22, the winding of RIBEl, the contacts I55, Hil and 222, and the windings of the magnet ifiii and the relay R2! in parallel to battery. The relay RZlFJ and the magnet Itil are insufiiciently energized in this circuit to operate. The magnet 26?, when energized in series with the transfer relay Rl lll, operates to advance the wipers. 2G and 262 one step from the illustrated normal positions thereof. When the wiper 29I is thus moved cit normal the initially traced operating circuit forthe transferrelay RI 513 is opened at this wiper and its associated first contact. Incide-nt to the operation of the wipers 2M and 2532 to the first oil-normal position, the off-nomal springs 205 are moved into engagement to prep-are the operating circuits for the reset relay R235 and the release magnet 234. i

As indicated above, at the end of the opencircuit period of the single impulse, the contacts E62 :are engaged to recomplete the circuit for energizing the pulsin relay RI I8. Incident to thisoperation the off-normal contacts I03 are disengaged, but without effect. The pulsing relay R! It, upon reoperating, recompletes the operating circuit for the hold relay RiZii and open its contacts I2 to deenergize the transfer' relay El ii? and the magnet 233. The magnet 293, when :dcenergized, retracts its operating armature .to condition the, associated ratchet and pawl mechanism to advance the wipers 20I and 202 a second step. The relay. R140, upon restoring, opens itscontacts M-I to= interrupt the above-traced looking circuit for the transfer relay RIEB. The relay Rlll'now restores and. opens [its contacts- I'5I further to intemup t this locking circuit. At its contacts I 53, the relay RI50 opens the abovetraced circuit for transmitting: current pulses to the magnet; 203; At its contacts I52, the relay R158 prepares. the circuit for energizing the transfer relay RIM in series with the vertical magnet I61;

When the second digit 5 of the number identifying the calling doctor is dialed: through operation of the transmitting device I Ma provided at the station A, the off-normal springs I03 are: again. moved into engagement and the pulsing. springs I02 are opened and closed six times, so that six impulses are transmitted to the=pulsing relay R'I'II'Ii At the beginning: of the open-circuit period of the first impulse, the relay RIIII restores to open the operating circuit for the: hold relay R120 and to close the above mentioned circuit for energizing the transfer relay'RMO in series with the vertical magnet I6I. The latter circuit extends from ground by way of the contacts H2 I21 and I531), the winding of RI GU, the contacts I 52, and the winding of the vertical magnet IB-I to battery. When thus energized, the relay RIM! opens its contacts I4 2 to prevent current pulses from being delivered to the rotary magnet I60 and the wipe out relay R216. At its contacts I43, the relay RIM] reprepares the path for by-passing the off-normal contacts I 832) in" the pulsing circuit. The vertical magnet I'SI, upon operating, functions to elevate the wipers 26f to 26 5, inclusive, one step in the vertical direction so that they are positioned opposite the first level of contacts in the associated contact field. Incident to this vertical motion of the wiper carriage structure, the offnormal springs I84 are operated into engagement to prepare the operating circuits for the reset relay R230 and the release magnet 294; the oil-normal springs I 632) are disengaged to interrupt the initially traced circuit for energizing the transfer relay RI '4!) and the vertical magnet I6I' in series; and the ofi-normal springs I53a aremoved into engagement to complete the prepared path, including the contacts I43, for bypassing the contacts ISBb in this circuit. Ac-

cordingly, the second and succeeding impulses of the second digit are repeated to the seriesconnected'transfer relay RM!) and vertical magnet IBI over a circuit which extends from ground by way of the contacts II'2, I2I, I631; and M3, the winding of RIM the contacts I52, and the winding of the magnet I8I to battery. Due to theslow-to release characteristics thereof, the relays RIZD and RME remain operated throughout the second digit. Each time the vertical'magnet I5! is energizedduring this digit it operates to elevate the wipers ZGI to 264, inclusive, an additional step. Accordingly, at the end ofthe sixth and last impulse of the digit, these wipers are left standing opposite the sixth level of' bank contacts in the associated contact field.

At the end; of the second digit, and during the inter-digit pause between the second and third digits, the pulsing relay RIIU'remains' operated' for asufficient time interval to" permit the deenergization and release of the transfer relay R149. Thisrelay, in: restoring, opens its contacts I43 I to interrupt the above-traced pulsing: circuit extending through its own winding and. the winding of the vertical magnet IE I. At

its contacts M2, the relay RMOf-urtherprepares the circuitfor energizing. the rotary magnet I- and thewipe outrelay RZI-Il inparallel.

When the; third: digit isdialed through operation ofthe transmitting; device I OIa provided at the station A,- five impulses are transmitted to This relay operates to the pulsing; relay RI I-IJ. repeat the-pulses to the parallel connected rotary magnet M50 and wipe out. relay REID over a circuit which extends from ground by way ofthe contacts I-I'2-, I-2I, ta3c, I42 and 222,. and the windings of the magnet I30- and the" wipe' out relay HMO to'battery. When energized over this circuit at the beginning ofthe third: digit, the relay R1210 operates and opens its contacts 2=I-I to interrupt the preparedcircuit for energizing the cut-off reIay'RZZS' in parallel with a selected one of the common wipe out relays; Due to: its slow-to-releasecliaractenistic the: wipe out rela-y R210: remains operated throughout the third: trainof impulses transmitted to the'pulsing. relay R'I-III. Each time therotary magnet I605 is emergizedl over the: pulsing circuit just tracedgit operates to rotate thewipers- 24% to 284 iii-- clusive; one step so that at the conclusion or the third digit these wipers" engage the associated' fifth-- contacts of the sixth level inthe associated" contact banks. Thus the relay equip ment individual to the display units for the doctor No; 165 is selected. Incident; to: the first rotary step of the wipers 2-6! to 284, inclusive; the oil-normal springs 206- are moved into engagement' to prepare the circuit for energizing the cut-01f relay R221) inparallel witl'r the c'ommon wipeout relay R300:

At the end of the third and final digit, the pulsing rela-y RIII) remains operated to cause the deenergization and release of the wipe out relay RZI'B. The'r l'ay- R240; in restoring, closes its contacts 2 I to oomplet e the above mentioned circuit for energizing the relays R220 and R300 in parallel. One branch of this circuit extends from ground byway oi the contacts 2H, the off-normal" springs 2G8; and the'win'di'ng of'RlZZfl to battery. Theother branch of'this circuit ex: tends from ground by" way of' the contacts 2'I I, theofif-normal-springsZDB'; thecon'tacts 221 and 255 the wiper 2'5'I- and the engaged sixty-fifth contact of its associated bank, and the winding of R380 to battery; When thus energized the relay R300 opens its contacts @III' to interrupt a point in the common portion of the locking circuits for the indicator lamp control relays R339; R345, etc; In the present case; this operation is without effect, but it Will be noted that had any one of the indicator lamp control relays been operatedi this control relay would have beenreleased by the relay R300 to cause the deenergization of theassociated indicator lamp:

Shortly following the operation of the relay REED, the slow-to-operate cut-off relay R opens its contacts 221 to cause the deenergizatiorrand release of the common wipe out relay R359. The relay- Rrlfianow restores to reprepare the locking circuits forthe control relays indi-- vidual to the'in'dicator lamps=ofthe display unit 25 and to the lamps of the other display units individual to the doctorNo. At its contacts 22?, th'erelay R220 opens-another point in the prev-iously't'raced circuit for transmittingcur-rent pulses-to'the rotary magn'et- I 90 and the wipe out relay Rain in parallel; Following the operation of the cut-ofi relay'Rzzll rio further operation or release magnet the apparatus occursuntil the automatic switch l is released at the station A.

In order to release the switch I l, and incident thereto to .cause the energization of the first floor indicator lamp 333 in the display unit and the first floor lamps of the corresponding display units ofthe other boards, the doctor No.-l65 must restore the key Gilda to its normal position. When this key is restored to normal the pilot lamps iilfia, 58512 and I850, and the pulsing relay R! It are deenergized inan obvious manner. In restoring, the relay Bl Ill opens its contacts! I! l to deenergizethe hold relay REZO, and closes its contacts 2 to prepare the above-mentionedoperating circuits for the reset relay R23Il and the release ma-gnet 264, as well as a circuit for energizing the control relayR33i! individually associated with the first floor lamp 333. The hold relay Rliltl, upon restoring, opens its contacts I22 to deenergize the release relay R138. When the latter relay restores'it closes its contacts I32 to complete the above-mentioned operating circuits for the relays E2353 and R338. These circuits commonly extend from ground byway of the contacts H2 and and the ofi-normal springs i6 3 and 265 in parallel, to the conductorilfid where they divide, one thereof extending through the winding of to battery and the second thereof extending by wayof the contacts 23!, till. 2M and 353, the wiper 262 and its engaged sixty-fifth contacts 55b of its associated contact bank, and the winding of R330 to battery. When thus energized the relay R333 locks to ground over a path including the contacts 33!, 322 and 33!. At its contacts 332, the relay R338 completes an obvious circuit for energizing the first fioor indicator lamp 333. It will be noted that parallel branches of the last-mentioned circuit extend to the first floor indicator lamps of the display units which are provided at the other display boards to indicate the location of the A contacts H2 andl32, the parallel-connected oilnormal springs Mid and 2 55, the conductor 23 5, the contacts 232, and the winding of the magnet 53M; to battery. At its contacts 333, the relay R2363 completes-an obvious circuit'for energizing the mechanism. lhe magnet 21%, upon operating, attracts its associated holding pawl to permit the spring-biased wipers 2M and 2552 to be returned to normal. Incident to the restoration of these wipers to their respective nornal positions, the oil-normal ings 235 are disengaged to interrupt one hran of the circuit over which the reset relay 323i is energized. The release magnet H32, upon operating, attracts its associated hold pawl to permit the wipers lotto 2264, inclusive, to be returned to rotary and vertical normal in the usual manner. Incident to the rel .se of the Strowger switching mechanism, the elf-normal springs 233 are disengaged to deenergize the cut-off relay R229; the vertical off-normal springs 535 are disengaged to cleanergize the reset relay R233; the vertical off-normal contacts are disengaged; and the v tical off-normal contacts H331: are moved into er ment. Thus the Strowger switching rnech. sin

832 of the Strowger switching 'tacts 365?) for a short time interval.

is fully restored to normal. Following the release of the tWo relays R220 and R233, the control equipment of the switch l l is completely released and this switch is prepared to handle another call.

It will be understood from the above explanation that, following the operations just described,

that the doctor No. 165 may be located on the first fioor of the hospital. If, after making routine calls or discharging other duties on this floor, the doctor No.165 proceeds to the second floor, he may, by dialing his identification numher at one of the second floor control stations, wipe out the indication displayedby the display unit 26 and the corresponding units of the other display boards, and reset these units to display an indication that he may now be located. on the second floor of the hospital. In this regard it Will be noted that, incident to the operation of the second floor switch I?! under the control of the calling second floor station, the wipers of this switch are positioned on the sixty-fifth contacts of the associated contact banks. Moreover,

immediately after the third digit 5 is dialed at the. calling second floor control station, the wipe out relay of the switch [2 operates to impress ground potential upon the contacts 36511 for a short interval, and thus energize the common wipe out relay R309. The manner in which this is accomplished will be clearly apparent from opens its contacts 332 to deenergize the first floor indicator lamp 333 of thedisplay unit 28 and .the

corresponding lamps of the other display boards. Thus the indications displayed by the display units individual to thedoctor No. are wiped out.

Upon concluding the dialing operation at the second floor control station in use, the doctor .No. may release the second floor, switch [2 by restoring the hold key of th second floor station in use to normal. Incident to the release oithe switch l2, the release relay thereof functions to impress ground potential upon the con- W'hen this contact is grounded the control relay R340 individual to the second floor indicator lamp 334 is energized in an obvious circuit. In operating,

the relay R340 locks to ground over a path including the contacts 3M, 312 and 38!, and closes its contacts 342 to complete a circuit for energizing the second floor lamp 33 in parallel with the corresponding lamps of the other display boards. Thus a new indication is set up in each of the display units individual to the doctor No. 185, which conveys the information that this doc- 'tor may be located on the second floor of the hospital.

It will be understood from the above explanation that a the doctor No. 165 proceeds from floor to floor of the hospital he may, by

- dialing his identification numberjat a control station on each floor, reset the display units provided for his use, so that accurateinformation is given at all times as to his location.

If the doctor No. 165 proceeds to a ward or floor where he will be occupied with duties from which he does not wish to be disturbed, he may wipe-out the indications displayed by the display units provided for his use, without resetting these display units to provide a new floor indication. For example, the doctor may be occupied for a time with duties in surgery, in which case he will not wish to be disturbed. In order to wipe out the existing indications displayed by the units provided for his use, the doctor No. 165 may dial the number 665 at any one of the control stations provided in the hospital. Assuming that this number is dialed at the first floor station A, for example, the first floor switch H is utilized in wiping out the existing indication. In this case the wiper 2B! and 202 of the minor switch 280 are positioned to engage their associated seventh contacts at the end of the first digit of six impulses dialed at the station A. With the wiper 2M in this position, a circuit including the resistor 26'! is completed for energizing the clear out relay R250. Aside "from the operation of the relay R240, the manner in which the relay equipment individual to the display unit 26 and the corresponding units of the other boards is selected and the operated control relay, such, for example, as the relay R340, is released, to wipe out the display of the existing indication, is exactly the same as described above. Also, the first floor switch H is restored to normal in response to the release of the hold key [Na in the exact manner previously explained. In this case, how ever, the relay R248 is held operated until after the reset relay R230 is caused to operate, in the manner explained above. Accordingly, the preveiously traced circuit for energizing the first floor control relay R530 is not completed. More generally stated, the release of the switch II is elTected without completing a circuit for energizing one of the control relay R330, R340, etc., individual 'to the indicator lamps of the display unit '26 and the corresponding units of the other display boards. Thus no new indications are posted in these units. ing the release of the first floor switch H, the clear out. relay R240 is deenergized and restores incident to the release of the minor switch 2'00. Otherwise the release of the switch *H is effected in the exact-manner described above.

If a :doctor, in attempting to change or Wipe out the indications displayed by the display units provided for 'use, proceeds to dial his identification number at one of the control stations without first operating the hold key provided at i this station, the automatic floor switch associated with 'the control station in use is released at the end of each digit and the pilot lamp at the control station in use is intermittently energized as the digits are dialed. Thus if the calling device lfi la at the station A is actuated before the hold key "Ma is operated to its ofi-normal position, the shunt springs 1'03 are closed as the dial of the device lil'la is moved on normal and are opened when this dial is returned to normal. During the period when these contact springs are :closed, the pilot "lamps 105a, 111%, I050, etc., and the relays R1 10, 'RI ZO, Rl3il, RM!) and RIBB are all energized in the manner previously ex- :plained. Moreover, the wipers of the minor switch 238 may be moved ofi" normal under the control of the magnet 203, through operation of the pulsing springs H32, during the period when the off-normal springs 4E3 are closed. When, however, these ofi-normal springs are opened, the

It will be noted that durlamps a, 1-057) and i050 and the relays RHO, RIZIJ, Rl30, RIM) and Rl'fifl are all deenergized and restore. Incident to the release of the relay -R|30, the wiper 262 is conn cted to ground at the contacts H2 in the manner previously described, but, under the conditions stated, the Wipers 26l to 264, inclusive, are at normal so that the application -of ground potential to the Wiper 2 62 is without effect. In releasing, the relay R|30 also completes the operating circuit for the reset relay R230. The reset relay, upon operating, completes 'the prepared operating circuit for the release magnets 204 and I 62. The operation of the magnet M2 is without effect. The magnet 2M, upon operating, permits the wipers 201 and 202 of the minor switch 200 to be restored to normal, in the manner described above, at which time the off-normal springs 285 are disengaged to deenergize the reset relay R230. 'Thusthe first floor switch H is .fully released and the pilot lamps 1115 are deenergized immediately after the first digit is dialed at the station A. Each time the transmittingdevice 'lll la is again actuated the operations just described are repeated, so that the pilot lamps I05 are intermittently energized. The flashing-of the 'lamp -|05a serves to inform the doctor using the control station A that the hold key 10 1a should be operated to its oil-norma'l position and that the dialing operation should be started over.

Each time a doctor leaves the hospital he is expected to comply with hospital regulations by operating his assigned out key at the lobby station 1'0, for the purpose of wiping out any indications which may be displayed by the display units provided Tor his use on the display boards. Thus, if "the control relay R380 of the display unit lfiisoperated, for example, and the doctorNo. 1"65 leaves the hospital, he is expected to actuate the "*out key l 65d when he passes the lobby station IO. When this key is momentarily operated to its off-normal position the contacts 16512 are opened to interrupt the locking circuit for the relay R310, the circuit for energizing the pilot lamp a and the circuit for energizing the parallel-connected pilot lamps PS5,, etc., of the various'display units individual 'to the doctor No. 165. The deenergization of the pilot lamps I556, I651, etc., indicates that the doctor No. 165 is no longer on 'the premises. Incident to the release of the relay R3ID, the contacts 31! are opened further to interrupt the circuits just considered, whereby the pilot lamps and the relay R3) are prevented from operating when the out key is released. At its contacts 3l2, the relay R310, upon restoring, interrupts the looking circuit for the operated relay R390. The relay R390 now restores to deenergize the indicator lamp 339 and the corresponding lamps of the other display boards. Thus all indications are wipedout'in the display units provided for the use of the doctor No. 165.

The manner in which the other doctors attached to the s'tafi of the hospital, and for whose use display units are provided on the display boards, may control the display units individual thereto from the lobby station J0, or any one of the control stations of the system, will readily be apparent from the preceding explanation. In this regard, however, it i pointed out that for selecting purposes the display units are divided into two groups ofone hundred sets each. With this arrangement, when the wipers of the Strowger switching mechanism embodied in any of the automatic floor switches are operated to any particular position, two sets of display units individual to two difierent doctors are selected. In order to determine which of the two selected sets of units is to be controlled, wiper switching relays are provided in each of the automatic floor switches. Thus the first floor switch ll includes a switching relay R2 50 which is controlled in accordance with the position of the wipers of the minor switch Zflil at the end of a first digit transmitted to the switch I I. With this arrangement, if the doctor No. 265, for example, operates the transmitting device Hlla to transmit the three digits of his identification number to the associated floor switch II, the wipers of the minor switch 200 are positioned to engage their associated third contacts at the end of the first digit of two impulses. Immediately the wiper engages its third contact an obvious circuit is completed for energizing the switching relay R258.

This relay, in operating, opens its contacts and 253 to interrupt the previously described circuits over which the relays individual to the doctor No. 165 are controlled. At its contacts 252v and 254, the relay R250 prepares circuits extending through the wipers 26 3 and 264, over which t the relays individual to the calling doctor No. 265 may be controlled in a manner clearly apparent from the preceding explanation. Aside from the operation of the switching relay R256, the wipe out of the indications displayed by the display unit 29 and the corresponding units of the other display boards and the resetting of these units to display first floor indications is efiected in the exact manner described above. In this regard it will be noted that the switching relay R250 is deenergized and restores in response to the release of the minor switch 230 during the release of the automatic floor switch H.

In the event a doctor, such, for example, as the doctor No. 265, having display units in the second group, desires to wipe out indications displayed by these units without resetting the units to display new indications, a first digit comprising seven impulses is dialed at the control station from which the wipe out is to be eiiected.

Assuming that the station A is used by the doctor No. 265 for this purpose, the wipers 2M and 202 are operated to engage their associated eighth contacts after the first digit of seven impulses is dialed at-the station A. With the wiper 20! engaging its associated eighth contact, the clear out relay B240 is operated to maintain thereset control circuits open, in the manner previously described. With the wiper 2B2 engaging its associated eighth contact,'the wiper switching relay R250 is energized so that the circuit for energizing the common wipe out relay R300 individual to the doctor No. 165 is held open at the contacts 25!, and the circuit for energizing the common wipe out relay individual to the doctor No. 265 is prepared at the contacts 252. Thus it will be apparent that with the wipers 283 and 264 engaging the contacts 265a and 265b, and the two relays R240 and R250 operated, the indications displayed by the display units individual to the doctor No. 265 will be wiped'out and no new indications will be displayed thereby incident to the release of the automatic floor switch I l.

Although the invention has been explained with reference to a system for indicating the location of doctors attached to the stafi of a large hospital, it will be understood that the system may also be used in industrial. and other organizations to indicate the location of other objects, both-animate and inanimate, in zoned areas which are not necessarialy different floors of a building. For example, the system may be utilized for indicating at one or more points the different locations of the executives and depart ment heads of a large industrial organization v having buildings disposed at random within a confined area. In such case the master or lobby station may be located at the gatehouse or entrance zone of the area. As a further example, the system may be used to indicate the location of loaded inter-departmental. trucks which are used in an industrial organization and are moved from place to place to meet production or other manufacturing requirements. Inorder generically to designate such persons or movable objects, the locations of which are to be indicated, such persons or objects have been termed subjects in the following portions of the specification.

While there has-been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is contemplated. to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimedis:

1. In a system for indicating the location of a plurality of subjects which may be located in different zones of a plural zone area, a display boardin said area including display units individuaily corresponding to said subjects, a control station including'signal transmitting means operative to transmit signals designating different ones of said '"units, each of said units being designated by two different signals, automatic switching means operative to select one of said units when either of the two signals designating said one unit is transmitted thereto from said control station, a device controlled by the transmitted signal and having two settings respectively corresponding to the two signals designating said one unit, means operative to wipe out an indication previously displayed by said one unit in response to the selection of said one unit by said switching means, means operative incident to the release of said switching means for causing said one'unit to display an indication of the zone wherein the subject corresponding to said one unit may be located, and means controlled by said device forpreventing the operation of said last-narned means when said device is operated to a predetermined one of its two settings'in response to, the signal transmitted to said switching means.

2. In a system for indicating the location-of a plurality of subjects which may be located in differentzones of a plural zone area, a display board in said area including display :units individually corresponding to. said subjects, a control station including signal transmitting means operative to transmit signals designating dificrent ones of said units, each of said units being designated by two signals of different character, automatic switching means operative to select one of saidunits when either of the two signals desig nating said one unit is transmitted thereto from said station, means operative in response to the selection of said one unit by said switching means for wiping out an indication previously displayed by said one unit, means operative incident to the release of said switching means forcausing said one unit to display an indication of the zone wherein the subject corresponding to said one :unit :may be located, and means selectively controlled in accordance with the character of the signal transmitted :to .said switching means for preventing the operation of .said last-named means.

3. In a system for :indicating the location of a plurality of subjects which maybe located in differentzones of aplural zone area, a display board in 'said area including display units individually corresponding'to said subjects, a control station including signal transmitting means perative to transmit signals designating difierent ones of said units, automatic switching means operative to select one of said units when the signal designating said one unit is transmitted thereto from said station, means operative in response to the selection of said one unit by said switching means "for wiping out an indication previously displayed by said unit, and means operative incident to the release of said switching means for causing said one unit to display an indication of the zone wherein the subject corresponding to saidone unit maybe located.

'4. In a system for indicating the location of a plurality of subjects which may -be located in diiierent zones of :a plural zone area, display boards individual to said zones and each includ- ;ingdisplay units individual to said subjects, control stations individual to said zones and each including signal transmitting means operative to transmit signals designating the difierent subjects, each of said subjects being designated by two signals-of difierent character, and automatic selector switches individual to said zones and each operative to select the display units corresponding to any one-of said subjects when either of the two signals designating said one subject is transmitted thereto, each of said switches including means for causing each of the selected units to wipe out any indication previously dis- ,played thereby and to display an indication of the zone inwhich the associated control station .is located and means selectively controlled in accordance with the character of the signal transmitted thereto for limiting the operation or" said last-named means to the wipe out of indications previously displayed by the selected units.

5. In-a system for indicating the location of a plurality of subjects which may be located in different zones of a plural zone area, display boards individual to said zones and each including display units individual to said subjects, control stations individual to said zones and each including signal transmitting means operative to transmit signals designating the difierent subjects each of said subjects being designated by two signals of diiierent character, automatic selector switches individual to said zones and each operative to select the display units correspending to any one of said subjects when either 0f the two signals designating said one subject is transmitted thereto, means operative incident to the selection of the units corresponding to one of said subjects by one of said switches for wiping out the indications previously displayed 6. In a'systemdorjndicating the :location of a plurality of subjects which may be located in difierent zones of a plural zone area, display boards individual to said zones and each including display units individual to said subjects, control stations individual to said zones, automatic selector switches individual to said zones and eachcontrollable from the associated control station to select the display units corresponding to any one of said subjects, means operative incident to the selection of the units corresponding to 'one of said subjects for wiping out the indications previously displayed by the selected units, and means operative incident to the release of said-one switch for causing the selected unitsto'display an indication of the zone wherein the control station corresponding to said one networksindividual to said subjects and each operative when seized from any one of said stations to wipe out the indications previouslydisplayed by the corresponding units, means including automatic selector switches individual to said zones for seizing said relay networks from said stations, and relays individual to said switches for eiiecting the operation of selected units to display an indication of the location of the control station from which each selected relay network is seized.

8. Ina system for indicating the location of a plurality of persons who may be located in different zones of a plural zone area :and who enter said area through an entrance zone, display boards individual to at least a portion of said zones and each including display units individually corresponding to said persons, means including automatic selector switches individual to said stations and adapted to be controlled from the respective corresponding stations for selecting the units corresponding to any person and for setting the selected units to :display indications of the zone wherein the person corresponding to the selected units may be located, an

entrance station in said entrance zone and including control switches individually corresponding to said persons, and means individually controlled by said control switches for rendering the corresponding display units controllable from said control stations and for controlling the corresponding units to display indications that the corresponding persons are in said area.

9. In a system for indicating the location of a plurality of persons who may be located in diiTerent zones of a plural zone area and who enter said area through an entrance zone, display boards individual to atleast a portion of said zones and each including display units individually corresponding to said persons, means inclucling automatic selector switches individual to said stations and adapted to be controlled from the respective corresponding stations for selecting the units corresponding to any person and for setting the selected units to display indications of the zone wherein the personcorresponding to the selected units may be located, an entrance station in said entrance zone and ineluding control switches individually corresponding to said persons, and means individually controlled by said control switches for wiping out for setting the selected units to display indicaing to the selected units may be located, an entrance station in saidentrance zone and including in and out controlswitches individually corresponding tosaid persons, and means individually controlled by said in switches for rendering the corresponding units controllable from said control stations and for controlling the cor responding units to display indications that the corresponding persons are in said area, said last-named means being individually-controlled by the corresponding out switches to wipe out indications displayed by the corresponding units.

HARRY E. HERSHEY.

tions of the zone wherein the person correspo'nd- 

